1. Field of the Invention
The invention relates to novel plastics-based high-strength materials and molded articles manufactured therefrom, which are degradable and resorbable in the human and animal organisms.
2. Discussion of Related Art
In the techniques of clinical surgery, substituting resorbable organic polymers for metal implants is desirable, because thereby a second surgery for removing the implants is rendered unnecessary. Today, resorbable suture materials and resorbable pins for the fixation of bone fragments are known in practical use. These materials used hitherto have been made of poly(lactic acid), poly(glycolic acid), poly(dioxanone) or of copolymers thereof.
The technical utilization of such materials in the form of resorbable plates, screws, nails and the like has failed to come so far. This is due to the following shortcomings, among others, of the materials known till today: The strength of the polymer is too low so that, for example, upon the use of said materials as bolts the heads crack off. There is a high dependency on the predetermined molar weight of the ultimate strength. Processing said materials is extremely expensive.
DE-A1 32 29 635 describes surgical binder systems for adhesion-bonding endogenous hard tissue optionally to plastics and/or metal. Here provided is a resorbable (meth)acrylate component which is liquid to solid at room temperature and consists of (meth)acrylic acid esters with (meth)acrylate moieties on oligoester chains of hydroxycarboxylic acids, said oligoesters having been formed of lower monohydroxymonocarboxylic acids. Here, organoboron compounds have been compulsorily prescribed as the polymerization initiator, which compounds are distinguished by a particularly high activity with respect to polymerization initiation. Said printed publication reporting results of Applicants' own studies was based on the recognition, that the combination of organoboron compounds as the initiator system with, more particularly, the polyfunctional (meth)acrylic acid esters can be especially appropriate for the necessary curing process to form high-strength joint bonds in the area of surgical adhesives.
In this older protective right there has also been referred to the demand for using resorbable supporting materials in surgical techniques, so that a second surgery as otherwise required would be rendered superfluous. Accordingly, in addition to the use of the reactive two-component system, said printed publication describes the use thereof for the in situ manufacture of resorbable molded articles in adhesion-bonding endogenous hard tissue, optionally together with plastics and/or metal. One indispensable component of the molded article formed thereby and, thus, an ingredient of the molded article to be implanted into the living organism is constituted by the organoboron compounds employed as initiators. To this day, materials of this kind have not gained general acceptance in practical use.